Dilhorne: Petrol in a Diesel Car? How Worried to Be
If it hasn't been started, worry far less than you likely are. Everyone in Dilhorne begins with "have I wrecked it?", and the fair answer is generally no: petrol left inside your tank of any diesel remains harmless until priming, cranking or driving pulls it into the fuel system. Petrol in Diesel is who to call, with the motor kept off, and so it stays that way. Further down, you will find what petrol really does inside a diesel, how far it might have got, and how to stop it happening to you a second time.
What petrol in a diesel does to the motor
Passing through an engine, diesel is doing two things at the same time. It combusts, and before it combusts it protects. Extremely fine tolerances go into the fuel injectors and the high-pressure pump, and only the diesel running through stops those surfaces grinding together.
Of these two jobs, petrol manages the first poorly and the second never. The rattling comes from petrol being made not to ignite when compressed, which is exactly the reverse of what a diesel needs. On top of that it is runnier than diesel, it strips out the protection the fuel system rests on, and any pump working on that blend is wearing itself.
Seen together, they show the shape the issue takes. Contact doesn't do the damage — movement does. Where the petrol is only in that tank, it's a fault of fuel, nothing more. The beginning of a mechanical one is a pump that has been labouring on that petrol — and whatever a worn pump sheds moves on with your fuel to the fuel injectors beyond it.
Petrol in a diesel around Dilhorne: how bad is it? Four situations
Fuelled, and not started: no case is better. Just the tank has petrol in it, and so the task is clearing that tank and flushing the fuel system where the vehicle stands. This scenario can only really take place on a forecourt: anywhere else, the vehicle got there by being driven.
Your ignition switched on, or a short start. Petrol has left your tank and got to the fuel filter and your lines, since your system has been primed. Drain, flush, deal with the fuel filter: still usually easy.
Those few miles on the road were the pump running on fuel weakened by petrol the whole way. The work is that tank, the fuel lines, the fuel filter and clean fuel through the whole system, and how hard your car was driven matters as much as how far. Short trips, like the school run to Dilhorne Endowed CofE Primary School, are one thing. Any distance on the M6, under 10 miles from Dilhorne, means the motor working hard throughout, and a run to Stoke-on-Trent, under 10 miles away, makes a very different task as well.
Driven till it protested. Knocking, a lumpy idle, smoke, a throttle that has gone soft. What you are hearing is the motor reporting fuel that no longer behaves like diesel. Whether it's the verge on Common Lane, a lay-by or a side road, stop there and leave it. The fuel drain and flush-through still come first, and they take care of it: if a vehicle is pulled over soon, long-term damage is very unusual.
Petrol in a diesel stories Dilhorne motorists hear
Myth: topping up to full with diesel makes it fine. It doesn't. Topping up removes nothing; it gives you a fuller tank of the same mix. Percentage isn't how a diesel fuel system tolerates petrol, whatever that advice supposes.
Myth: a modern diesel copes with a bit of petrol. Rather, the opposite. Smaller parts and higher pressure are how a newer diesel runs its fuel, and that makes the protection count more, not less.
Myth: "If it starts and drives, there's no damage done." This is the one that fools people. Diesel in a petrol motor generally leaves a motor that will not run: the driver stops, and so does the harm. Feed petrol to a diesel and it usually fires up, idles and pulls away like nothing happened — all while its pump is wearing. Fine and running are not the same thing.
Not so: a two-stroke additive lets you to drive home. It is an old workaround, supposed for another fault. It does not put back what petrol has thinned, and that petrol is still in the tank later on.
The next start draws petrol back round the pump out of the lines and the fuel filter, where some of that ends up after the engine has been run. That is why draining your tank yourself doesn't sort it — a myth. Also, a can of petrol drained at the kerbside is genuinely risky.
Why petrol in a diesel occurs so easily
A careless moment is seldom the cause, and nobody means to do it. The forecourt makes it simple: the petrol nozzle is the narrower of the two, and it slips into a diesel filler with almost no resistance, whilst a diesel nozzle mostly won't go into a petrol car at all. So the slip runs one way.
It happens when routine and your car stop matching. Courtesy car, hire car, or a car that is brand new. Two cars on one driveway, one petrol, one diesel. The pumps in a different order on a well-known forecourt. Racing for a train outside Blythe Bridge and filling up en route. Precisely the moment it occurs: after years of driving petrol, someone fills a diesel Volkswagen Passat for the first time. Throw in rain, a phone call or a back seat full of kids, and your hand does what it has always done.
Preventing petrol in a diesel next time you fill up around Dilhorne
- Check the pump, not the colour. In the UK unleaded handles are generally green and diesel black, but not on every forecourt. The label is what matters.
- Plenty of motors state the fuel inside your filler flap or on the cap, so check it on your first fill in a car you don't know.
- Label the key. In a household with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of intending to remember.
- Before the nozzle comes off the pump the first time you fuel a hired or new car, say "diesel" aloud. Daft, perhaps, but it works.
- Put your phone away. This is an easy mistake to make whilst you're thinking about something else.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler designed to reject a petrol nozzle, and add-on devices are available for the remainder. Treat it as a safety net, then keep checking the pump.
- Stop as soon as you realise. Less petrol in your tank makes a weaker mixture. It does not change what to do next, which is still not to fire it up.
Dilhorne: already put petrol in a diesel?
Then the order of things is short. Don't switch the ignition on, and do not start it. If you're still on the forecourt — Knights Of Cheadle or anywhere else — ask the attendants to help you roll it clear of the pump. What went in, roughly how much, and if it has run: tell us that when you call 0333 366 0103.
If it was AdBlue instead of petrol, say so. That's a different issue — corrosion and deposits and not lost protection — and it has its own page for Dilhorne.
One petrol in a diesel job in Dilhorne costs more than another. Why?
The four scenarios above are four separate tasks, so no single price for this would be fair. The situation itself does most of the work of moving your cost. Two things follow that: the petrol that went in as a share of what that tank holds, then the spot the car is in and whether a technician can get to it safely.
Ahead of any quote, not after, come three queries: the fuel that got in, its quantity, and whether it has run. That is why. Their answers are what turn a range into one firm number.
About Dilhorne, briefly
Dilhorne is a small village in Staffordshire, situated approximately 6 miles north of Stoke-on-Trent, and is characterised by its detached housing stock. Dilhorne sits at an elevation of 219 metres, in a rural area surrounded by nearby places such as Godleybrook, Boundary, and Whitehurst. Dilhorne has a population of around 522 residents, and is located inland, about 130 miles northwest of London. Dilhorne remains a quiet, residential community with a strong sense of locality.
Dilhorne and Staffordshire: where our fuel drain cover runs
Petrol in diesel jobs around Dilhorne — part of the ST postcode area — go to vans that likewise cover the locations around it, Godleybrook, Boundary and Whitehurst among them. The vehicle does not need to come to us: we drain on a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
Dilhorne: still at the petrol pump?
Then you're in the best place there is. Phone, and keep it switched off.